The present invention relates to a manipulator having joints disposed a supporting base such as the body portion of a robot, etc.
Recently, unmanned operation and control have progressed in factories and power generation plants, and in particular, places where there is a very high degree of danger. In line therewith, various types of manipulators have been developed, which carry out work for workers.
A drive part built-in type in which the drive part such as a motor is incorporated in respective joints and a wire rope type in which a plurality of joints are driven by a drive portion such as a single motor with a trailed wire rope have been known as the prior art manipulators.
However, the abovementioned prior art manipulator has the following problems and shortcomings.
(1). Since, in a drive part built-in type manipulator, the drive part is incorporated in respective joints, the entire manipulator is heavy in weight, and it is necessary to increase the torque of members, which support the manipulator, (for example, a motor at the base of the manipulator and a motor for moving the entire apparatus). Therefore, the entire apparatus is accordingly heavy in weight, whereby operation efficiency is reduced along with a worsening of production efficiency.
(2). Since, in the drive part built-in type manipulator, it is necessary to secure a space for providing a drive part in respective joints, the manipulator itself is increased in scale, accordingly, the entire apparatus is also made larger, whereby operation efficiency is reduced along with a worsening of production efficiency.
(3). Since, in the wire rope type manipulator, a plurality of joints are interlockingly actuated by driving a drive part such as a single motor, etc., it is difficult to cause the joints to move complicatedly, and operation efficiency is worsened.
The invention was developed to solve the problems and shortcomings inherent in the prior arts. It is therefore an object of the invention to provide a manipulator comprising a wire for transmitting the power of a motor(s), and a flexible tube in which the wire slides, wherein, since said motor is disposed in the body portion of a robot other than the manipulator, and respective joints are driven by the respective motors, it is possible to make the manipulator small and light, to save power consumption, to improve the operation efficiency and to secure excellent production efficiency.
In order to solve the above object, the manipulator according to the invention has the following constructions.
A manipulator of the invention is disposed at the body portion of a robot or a supporting base such as a rack, at a work site, etc., and has one or more joints and a mechanism for moving and rotating the joints; wherein the moving and rotating mechanism is provided with pulleys secured at the joints; an endless wire which is rotated by motors each disposed at an appointed position on the supporting base and has an appointed portion fixed at the pulley; and a flexible tube having one end fixed in the vicinity of the side of the pulley and the other fixed in the vicinity of the motor, into which the wire is inserted; and wherein one of the motors is disposed for one of the pulleys.
With the abovementioned construction, the following effects can be brought about.
(1). The endless wire is rotated by driving the motor, whereby the pulley is rotated, resulting in rotation of the joints.
(2). Since the wire passes through the flexible tube, the pulley can be directly driven by the drive part even though obstacles such as other members reside between the pulley and the drive part.
(3). Since the motor is not disposed at the manipulator but is disposed on the supporting base such as the body portion of a robot, no space is required to dispose the motor(s) at the respective joints. Therefore, the distance between the respective joints can be shortened, whereby it is possible to make the manipulator small in size and light in weight. By making the manipulator small in size, a downsizing of the entire apparatus (for example, a robot) having the manipulator can be achieved, and transferability thereof can be improved. Therefore, operation efficiency can be much improved, whereby operation can be carried out even in a small space. Also, by lightening the weight of the manipulator, the torque of a motor for the part (for example, the base of an arm) that supports the weight of the entire manipulator and of a motor for moving the entire apparatus can be reduced. Therefore, power consumption can be saved.
(4). Since one pulley is provided for one motor, individual motors can be independently controlled, whereby the respective joints are caused to execute actions independent from the other joints. That is, complicated actions can be carried out, and operation efficiency is excellent.
Herein, it is recommended that an adjuster to adjust the length of the flexible tube is provided at the terminal end of the flexible tube, which can deal with elongation of the wire.
A manipulator of the invention is disposed at the body portion of a robot or a supporting base such as a rack, at a work site, etc., and having one or more joints and a mechanism for moving and rotating the joints; wherein the moving and rotating mechanism is provided with pulleys disposed at the joints; a linear wire having one end thereof fixed at the pulleys and the other end thereof fixed at an appointed portion of the supporting base and connected to the motors; a flexible, tube having one end fixed in the vicinity of the side of the pulley and the other fixed in the vicinity of the motor, into which the wire is inserted; and a resilient body disposed in engagement with the pulleys, which contracts as the motors wind up the wire; and wherein one of the motors is disposed for one of the pulleys.
With the abovementioned construction, the following actions can be brought about.
(1). The joints can be moved by driving the motors in the direction of winding up the wire. Also, as the motor is driven in the direction of unwinding the wire, the joints can be moved in the reverse direction by the restoration force of a contracted resilient body.
(2). Since the wire passes through the flexible tube, it is possible to directly connect the wire from the drive part to the pulley even though obstacles such as other members exist between the pulley and the drive part.
(3). The motor is not disposed at the manipulator, but is disposed on a supporting base of the body portion of a robot, etc., no space is required to arrange the motor at the respective joints, whereby it is possible to shorten the distance between the respective joints, and make the manipulator small in size and light in weight. By making the manipulator small in size, the entire apparatus (for example, a robot) having the manipulator can be made small in size, and transferability thereof can be improved. Therefore, operation efficiency can be much improved, whereby operation can be carried out even in a small space. Also, since the torque of a motor for the part (for example, the base of an arm) that supports the weight of the entire manipulator and of a motor for moving the entire apparatus can be reduced. Therefore, power consumption can be saved.
(4). Since one pulley is provided for one motor, individual motors can be independently controlled, whereby the respective joints are caused to execute actions independent from the other joints. That is, complicated actions can be carried out, and operation efficiency is excellent.
Herein, a spring structure such as a twisted coil spring or a rubber body, etc., may be used as a resilient body.
It is recommended that ah adjuster to adjust the length of the flexible tube is provided at the terminal end of the flexible tube, which can deal with elongation of the wire.
A moving and rotating mechanism is disposed at joints where it is necessary to detect the tension thereof, and a moving and rotating mechanism is disposed at joints other than the above, whereby more complicated and highly accurate work can be carried out.
The invention is also directed to a manipulator which is provided with a tension detecting mechanism disposed at an appointed point on the wire and which enables detection of the tension of the wire.
With the abovementioned construction, the following additional actions can be brought about.
(1). By detecting the tension of the wire and feeding it back to the operation portion of joysticks or the operation side of the display portion, etc., of a CRT, it is possible to prevent an accident in which excessive winding of the wire by the motor occurs. Therefore, safety is excellent.
(1). By detecting the tension of the wire and feeding it back to the operation portion of joysticks or the operation side of the display portion, etc., of a CRT, it is possible to prevent an accident in which excessive winding of the wire by the motor occurs. Therefore, safety is excellent.
Herein, a potentiometer, a resistance strain type sensor or a crystal type force sensor may be employed as a tension detecting mechanism. Also, a torque sensor which detects the torque of the motor may be also used.
The invention is also directed to a manipulator, wherein the tension detecting mechanism is provided with a tension pulley having one end thereof brought into contact with an appointed portion of the wire, which is disposed slidably in the vertical direction along the wire; a traction means for tracking the tension pulley to the wire side; and a potentiometer, whose resistance value varies in line with the amount of movement of the traction means, disposed at an appointed portion of the traction means.
With the abovementioned construction, the following additional actions can be brought about.
(1). An appointed portion of a wire presses and moves the tension pulley in proportion to the tension of the wire, and in line therewith, the traction means moves and the resistance value of the potentiometer varies. Therefore, it is possible to detect the tension of the wire by using the degree of changes in the resistance value of the potentiometer.
As described above, according to the manipulator of the invention, the following advantageous effects can be brought about.
(1). An endless wire can be moved and rotated by driving the motor, whereby the pulley also moves and rotates, and accordingly, the joints move and rotate.
(2). Since a wire is inserted into the flexible tube, it is possible to directly drive the pulleys from the drive portions even though obstacles such as other members exist between the pulleys and drive portions.
(3). Since the motors are not disposed at the manipulator, but are disposed on a supporting base such as the body portion of a robot, no space is required to install motors at respective joints, whereby it is possible to shorten the distance among the respective joints, and the manipulator can be easily lightened and down-sized. By down-sizing the manipulator, the entire apparatus (for example, a robot) including the manipulator can be also down-sized. Therefore, the transferability is excellent, and working efficiency can be further improved since work can be carried out in narrow spaces. Also, since the torque of a motor for a part (for example, the base of an arm) which supports the weight of the entire manipulator and of a motor for moving the entire apparatus can be reduced by lightening the weight of the manipulator, power consumption can be saved.
(4). Since one pulley is provided for one motor, individual motors can be independently controlled, whereby the respective joints are caused to execute actions independent from the other joints. That is, complicated actions can be carried out, and operation efficiency is excellent.
Herein, it is preferable that an adjuster to adjust the length of a flexible tube is provided at the end portion of the flexible tube, because it can deal with elongation of the wire.
According to another aspect of the invention, the following effects can be brought about.
(1). The joints can be moved by driving the motors in the direction of winding up the wire. Also, as the motor is driven in the direction of unwinding (sending out) the wire, the joints can be moved in the reverse direction by the restoration force of a contracted resilient body.
(2). Since the wire passes through the flexible tube, it is possible to directly connect the wire from the drive part to the pulley even through obstacles such as other members exist between the pulley and the drive part.
(3). The motor is not disposed at the manipulator, but is disposed on a supporting base of the body portion of a robot, etc., no space is required to arrange the motors at the respective joints, whereby it is possible to shorten the distance between the respective joints, and make the manipulator small in size and light in weight easily. By making the manipulator small in size, a downsizing of the entire apparatus (for example, a robot) having the manipulator can be achieved, and transferability thereof can be improved. Therefore, operation efficiency can be much improved, whereby operation can be carried out even in a small space. Also, by lightening the weight of the manipulator, the torque of a motor for a part (for example, the base of an arm) which supports the weight of the entire manipulator and of a motor for moving the entire apparatus can be reduced. Therefore, power consumption can be saved.
(4). Since one pulley is provided for one motor, individual motors can be independently controlled, whereby the respective joints are caused to execute actions independent from the other joints. That is, complicated actions can be carried out, and operation efficiency is excellent.
According to another aspect of the invention, the following additional effect can be brought about.
(1). By detecting the tension of the wire and feeding it back to the operation portion of joysticks or the operation side of the display portion, etc., of a CRT, it is possible to prevent an accidental excessive winding of the wire by the motor. Therefore, the safety is excellent.
According to another aspect of the invention, the following additional effect can be brought about.
(1). An appointed portion of a wire presses and moves the tension pulley in proportion to the tension of the wire, in line with which the traction means moves and resistance value of the potentiometer varies. Therefore, it is possible to detect the tension of the wire by using the degree of change in the resistance value of the potentiometer.